NEGATIVE ELECTRODE PLATE, SECONDARY BATTERY AND METHOD FOR PREPARING SAME, BATTERY MODULE, BATTERY PACK, AND ELECTRICAL APPARATUS
A negative electrode plate includes a negative electrode current collector and a negative electrode film layer on at least one surface of the negative electrode current collector. The negative electrode film layer includes a negative electrode active material, a metal hydride, a conductive agent and a binder. The negative electrode active material includes a silicon-based negative electrode active material.
1 . A negative electrode plate, comprising:
a negative electrode current collector; and
a negative electrode film layer on at least one surface of the negative electrode current collector, the negative electrode film layer comprising a negative electrode active material, a metal hydride, a conductive agent and a binder, wherein the negative electrode active material comprises a silicon-based negative electrode active material.
2 . The negative electrode plate according to claim 1 , wherein the metal hydride has a general formula MH x , where M is selected from at least one of Na, Mg, Ca, and Al.
3 . The negative electrode plate according to claim 1 , wherein the metal hydride in the negative electrode film layer has a mass percentage of 5% to 35%.
4 . The negative electrode plate according to claim 1 , wherein a mass ratio of the silicon-based negative electrode active material to the metal hydride is 1:(0.5-3.5).
5 . The negative electrode plate according to claim 1 , wherein the negative electrode active material further comprises a carbon-based negative electrode active material.
6 . The negative electrode plate according to claim 1 , wherein a mass ratio of the silicon-based negative electrode active material to the carbon-based negative electrode active material is 1:(4-10).
7 . The negative electrode plate according to claim 1 , wherein:
the silicon-based negative electrode active material is selected from at least one of elemental silicon, a silicon oxide, a silicon-carbon compound, a silicon-nitrogen compound, and a silicon alloy; and/or
the silicon-based negative electrode active material has a median particle size Dv50 of 3 μm to 10 μm; and/or
the silicon-based negative electrode active material in the negative electrode film layer has a mass percentage of 3% to 20%.
8 . The negative electrode plate according to claim 1 , wherein:
the carbon-based negative electrode active material is selected from at least one of artificial graphite, natural graphite, soft carbon, and hard carbon; and/or
the carbon-based negative electrode active material has a median particle size Dv50 of μm to 30 μm; and/or
the carbon-based negative electrode active material in the negative electrode film layer has a mass percentage of 30% to 80%.
9 . A secondary battery, comprising:
a positive electrode plate;
a separator;
an electrolyte; and
the negative electrode plate of claim 1 .
10 . The secondary battery according to claim 9 , wherein in the negative electrode plate, a particle surface of the silicon-based negative electrode active material contains metal or metal lithium alloy and lithium hydride, and the metal is selected from at least one of Na, Mg, Ca and Al.
11 . A method for preparing the secondary battery according to claim 9 , comprising:
performing constant-voltage discharge treatment at 0.45±0.1V 0.5 hours to 1.5 hours and at 0.23±0.1V for 0.5 hours to 1.5 hours.
12 . A battery module, comprising the secondary battery according to claim 9 .
13 . A battery pack, comprising the battery module according to claim 12 .
14 . An electrical apparatus, comprising the secondary battery according to claim 9 .